Gas metal arc welding has several advantages over other types of welding including high deposition rates, speed, excellent weld quality, minimal distortion of the work piece and no stub loss. Typically, a conventional metal inert gas (MIG) apparatus includes a torch and a wire electrode continuously fed from a supply reel or other source by an electrode wire feeder through the torch. An arc between the torch and the work piece continuously melts the wire electrode to form the weld puddle.
Heretofore, electrode wire feeders have included opposed feed rolls which exert a pressure on the electrode wire passing therebetween and are driven by meshing gears to feed the electrode wire to and through the torch. In some instances, a single pair of opposed feed rolls are used, while in other instances two pairs of feed rolls are utilized in spaced relation along the feed path of the wire.
During use, the electrode wire is threaded between the opposed feed rolls, and thus, provision must be made to form a gap therebetween for threading-up purposes and for closure of such a gap for operational purposes. Typically, one of the feed rolls of the pair or each of the pairs of feed rolls is mounted for movement between operative and inoperative positions to provide for formation and closure of such a gap.
One issue with existing wire feeders is that the manner in which the pair of feed rolls is released from the operative position involves the use of a clamping lever that is not conveniently operated because it can interfere with other internal components of the welding device. Another issue is that existing wire feeders are designed to receive a single set of drive reduction gears, thus limiting the wire feed speed to a single value or an undesirably narrow range of values. Yet another issue is that existing wire feeders are typically provided with a generic torch connection, which thus requires the provision of one or more separate adapters to connect to a particular style of torch.